The development of more portable assessment techniques of cognitive and vestibular characteristics has been well documented by researchers and innovators. Techniques for assessing subject memory, reasoning, discrimination, intellect, etc., using mobile devices have been developed. However, reaction time has not shown consistent measures. The high variability in mobile device touch-screen based reaction time testing presents a problem for accurate assessment of reaction time that is not typically seen with desktop/laptop computer-based approaches that record reaction time with mouse clicks or pressing a key such as the space bar.
Reaction time is a measure of sensory and neuromotor function that encompasses stimulus recognition and processing followed by the initiation of a neuromotor response. Reaction time can be tested with varying levels of difficulty in the sensory phase, or the neuromotor response phase. The Simple Reaction Time (SRT) test is the most elementary form of reaction time measurement, which looks at signal processing of a single stimulus with a defined physical response, such as pressing a button.
Reaction time is typically evaluated digitally via a computer program running on a desktop computer, which measures the time lapse between stimulus presentation on the screen and the touch of a keyboard or click of a mouse. More practical and accessible tools for reaction time assessment have been suggested, however these tools are typically not digitally connected for archiving individualized comparative measurements and require equipment that is not always available outside of the clinic.
Computerized testing is generally accepted as the gold standard for reaction time assessment. Inherent in the reaction time measurement is a time lag (latency) between the time a key is depressed and when it is registered by the computer. Computerized testing remains popular despite mouse and keyboard latency variations of 20 to 50 milliseconds between commercially available models. Additionally, a practical limitation of computerized testing is the immobility of the testing platform.
Recent efforts to promote cognitive assessment on mobile devices have attempted to address the portability issue in computerized testing with the use of touch screen devices such as cell phones. A transition to touch screen reaction time assessment has been slowed due to latency in the touch identification mechanisms of mobile devices. Recent studies have failed to produce statistical equivalence between touch-based reaction time assessment and computerized testing.
More concerning is the latency caused by delays between the time when a user's finger contacts a touch screen and the time that contact is registered by the CPU. This can introduce inaccuracies into measured reaction time values. In some cases, depending on the hardware and software resident within the mobile device, the latency might be between 20 and 100 milliseconds (i.e., between about 0.020 and 0.100 seconds). With average human simple reaction time scores of 230 ms, and standard deviation of 20 ms, the current touch screen latency does not provide a medium for accurate measures. A small sample of neurocognitive testing on a mobile device showed slower and more variable measurements of response times when compared against computerized models. There remains a critical need for more accurate reaction time measures on touch-screen portable computing devices.
Additionally, user experience inconsistencies in the touching action with variability of initial finger distance from the screen create inconsistencies in accurately measuring response time. Distance of the finger from the screen had a significant effect on reaction time score. Additional use cases have been presented where the user begins with screen contact and removes the finger as a capture of response to stimulus. This action has an improved accuracy of reaction time score, but still contends with the scanning rate of the run loop and screen input latency.
In short, the technical translation of touch screen reaction time detection to this point may fail to accurately measure reaction time in both simple and choice reaction time trials.
As such there has been, and remains, a critical need for more accurate reaction time measures on touch-screen portable computing devices.
Heretofore, as is well known in the cognitive testing industry, there has been a need for an invention to address and solve the disadvantages of prior art methods. Accordingly it should now be recognized, as was recognized by the present inventors, that there exists, and has existed for some time, a very real need for a system and method that would address and solve the above-described problems.
Before proceeding to a description of the present invention, however, it should be noted and remembered that the description of the invention which follows, together with the accompanying drawings, should not be construed as limiting the invention to the examples (or preferred embodiments) shown and described. This is so because those skilled in the art to which the invention pertains will be able to devise other forms of the invention within the ambit of the appended claims.